Duplicated work in Rosetta/Debian -- how to avoid

[Tim Morley]

Hi all.

I've got what I think is a very elementary question about using  
Rosetta, and I'd be grateful for an answer in simple words of one  
syllable, please!

A colleague has translated some of the Debian installer, and his work  
has been picked up and added to Rosetta. Some other people have added  
to and corrected his work within Rosetta, but he wasn't aware of it,  
and he's since carried on translating at home, duplicating some of  
the work done in Rosetta, and not benefiting from the corrections in  
Rosetta.

Question 1: What's the best way to merge the two existing versions  
(from Rosetta, and from his work done privately)?

Question 2: More importantly, what's the best way to avoid this in  
the future?

NB The answers are probably going to include the words "upstream" and/ 
or "downstream", and I'd be grateful for a 30-second Dummies Guide To  
What Upstream & Downstream Mean in the context of Rosetta/Launchpad.

Thanks in advance.


Tim